docs: def default(self, value):
          """
          Handle UUID, datetime, and callables.
  
          :param value: Value to encode
          """
          if isinstance(value, uuid.UUID):
              return str(value)
          elif isinstance(value, datetime.datetime):
              return value.isoformat()
          elif callable(value):
              return str(value)
          return json.JSONEncoder.default(self, value)